Why is King John the classic villain?

A new film about King John further underlines history's judgement of the medieval English monarch as a cruel tyrant. But among the dozens of bad kings and despots, why is John always the pantomime villain?

Surrendering lands in France, forced into a humiliating climbdown with the nobility and ex-communicated by the Church. Not to mention being blamed for the murder of his nephew.

The medieval reign of King John has been characterised by disaster and his reputation languishes among the lowest for all the kings and queens of England.

This poor standing is illustrated by his persistently negative appearances in British cultural life 800 years on. Depictions on television, stage and big screen, particularly in Robin Hood films, usually present a man who is treacherous and weak....